Flow-meter.



L-A-SHELDON.

FLOW METER,

OATION FILED B13013 1913 Patented Dec. 1, 1914.

' |n\/en-t \z Lucian Asheldon UNITED V STATES PATENT OFFICE.

LUOIAN A. SHELDON, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK.

now-Maren i Specification-of Letters Patent.

Patented Dec. 1, 1914.

Application filed December 18, 1913- Serial 1T0. 866,412.

To all whom itmay concern:

Be it known that I, LUCIAN A. Summon, a citizen of the United States, residln at Schenectady, county of Schenectady, tate of New York, have invented certain new and useful Improvements in Flow-Meters, of which the following is a specification. 4

My invention relates to flow meters and particularly to such instruments wherem motion is transmitted from the element which moves responsive to changes in the rate of flow to the indicating element or pointer through the instrumentality of a suitable magnet or magnets. In such a motion transmitting means a magnet 1s mounted inside and adjacent a wall of the flow meter casing, to which magnet movement is transmitted through suitable mechanism by variations in the rate of flow of the fluid being metered. Either the entire casing or the portion thereof adjacent the magnet 1s constructed of non-magnetic material and suitably mounted outside the casing and oposite the magnet is a second magnet'which, due to magnetic action, moves in union with the'magnet in the casing.

- In order to insure accuracy in the reading of the instrument, it is essential that there be relatively strong magnetic action between the magnet inside the casing and the magnet outside, and heretofore in cases where the reluctance of the magnetic path was relatively great, due to the distance apart of the magnets, it has been necessary to usequite powerful magnets.

Occasions when the magnetic path between the magnet insidelthe casing and the magnet outside is relatively long may arise due to the desirability of placing the pointer or indicating element some little distance from the casing, or due to the necessity of constructing the wall of the casing of relatively thick material as in cases where fluid under high pressure is being metered.

The object of the present invention is to provide means for reducing the magnetic re luctance of the path between the magnet inside the casing and the magnet outside whereby even though the distance therebetween be relatively great it is unnecessary to use more owerful magnets in order to obtain :the esired magnetic faction. To this end I provlde means for decreasing the magnet1c reluctance of the path between the magnets which means may take'the form of pins of magnetic material and of low magnetic reluctance having one end embedded in the casing and arranged in the path of the magnetic flux.

' In the accompanying drawing which illustrates an embodiment of my invention, Fig-' ure 1 is a sectional view of a flow meter em bodying my improvements, and Fig. 2 is a face view showing the arrangement of the magnetic pins.

I have illustrated a flow meter of the U- tube mercury type, the casing 3 of which is provided with the openings 4 and 5 into which are connected the leading and trailing pressure transmitting pipes as is customary and well known. The tube has a body of mercury therein upon which rides the float 6 suitably connected as by flexible cord, chain or other device 7 to the grooved wheel 8 carried by the pivot shaft 9. Mounted on this shaft is a small pulley wheel 10 to which is attached the cord 11 of the counter weight 12, which to a greater or less extent counterbalances the float -6.

The shaft 9 is shown as being pivoted in a frame 11 and upon the end thereof adjacent to a wall of the casing is mounted a magnet 13. This magnet is shown as being mounted at its center and having its ends turned toward the casing so as to direct the magnetic flux. In the present instance. the casing proper is illustrated as being made of magnetic material and having opposite the magnet 13 an opening into which is threaded a plug 14 of non-magnetic material, as copper. This plug is hollowed out to receive the magnet 13 so that the magnet is entirely surrounded except at the rear by non-magnetic material. Mounted on the plug is a site the ends of the magnet The magnet 19 carries a pointer 20 which plays over a suitable scale on the annular plate. 21.

Located in the path of the magnetic'flux between the inturned ends of the magnets 13 and .19 is a series of pins '22 formed of magnetic material, as soft iron. These pins 22 are inserted in holes bored part way through the face of the plug and-are s aced apart sufliciently so as not to material y detract from the strength of the plug. The pins are illustrated as projecting slightly beyond the face of the plug 14, but this is only by way of example, as said pins might be flush with-the surfaceof the plug or project quite some distance as found desirable In any particular case. 'In fact, in actual practice, these pins might be made of considerable length so that the magnet 19, pointer 20, and scale 21 could be located at some convenient and readily accessible point quite remote from the instrument proper, it being only necessary that the magnetic through the pins be of greater permeabllity than that through the air.- At the points where these pinsare located the magnetic reluctance of the path is've'ry'much reduced so that at said points the lines of force tend to concentrate, and, therefore, in order to obtain a uniform movement of the magnet.

19 in response to movements of magnets 13 I provide an odd number of equally spaced pins 22 as best shown in Fig. 2. Due to this arrangement there are no oppositely disposed pins and hence the opposite ends of the magnets 113' and 19 can never at the same time lie directly over two pins only. As aresult the pull between the magnet 19 andmagnet 13 will be substantially uniform at all points, and any tendency-toward. jerky or step by step movements; as, would'otherwise be the case, is obviated. I' do not, however, desire to limit my invention to the use of a single row of pins of odd number, as I may usemore than one row of pins, as for example, two rows or three rows, the pins of the respective rows bein staggered with respect to each other. Un er these circumstances it is not essential that I use an odd number in each row as practically a uniform magnetic path will be formed between the maIgnets in the annular path of the pins.

n'accordance with. the provisions of the patent'statutes, I have described the principle ofoperzition of my invention together with the -apparatus which I now consider'to re'resent the best embodiment thereof; but

- I esire' to have it understood that the appaby Letters'Patent of the United States, is

ratus shown is only illustrative, and that the invention can be carried out by other means. 'What I cla1m as 'new and desire to secure 1'. The combination with a movably mountpath ed magnet, of a second movably mounted magnet spaced therefrom and adapted to' follow the movements of the first'magnet,

a wall of non-magnetic material between the magnets, and means of relatively high per-' meability embedded in the wall in the., .path

of the magnetic flux for reducing the 'reluctance of the magnetic path between the magnets.

' 2. The combination with a movably mounted magnet, of a second movably mounted netic flux for reducing the reluctance of the magneticpath between the magnets.

3. The combination with a movably mounted magnet, of a'second-movably mounted magnet spaced therefrom and adapted to follow the movements of the first magnet, a

wall of non-magnetic material between the magnets and spaced ins formed of a material o relatively high permeability em-v bedded in. the wal in the path of the magnetic flux for reducing the reluctance of the magnetic ath between the magnet and the member, t iere being an odd number of such pinsfor the purpose described. N

4. The combination in a flow meter having at least a portion of its casing formed of non-magnetic material, of a magnet pivotally mounted within the casing adjacent the.

non-magnetic portion of the wall, means for transmitting movements to said magnet, a second magnet mounted outside the casing directly opposite to the first named magnet adapted to movein unison therewith, and

pins of magnetic material having their ends embedded in the casing in the path. of the flow of magnetic flux for reducing the reluctance'of the magnetic path through the easm J The combination in a flow meter having at least a portion of its casing'formed'of non-magnetic material, of a magnet pivotally mounted within the casing adjacent the non-magnetic portion of the wall, means for transmit-12mg movements to said magnet, a second agnet mounted outside the casing directly opposite to the first named magnet adapted to move in unison therewith, and

pin of magnetic material having their ends embedded in the casing in the path'of the flow of magnetic flux for reducing the reluctance of the magnetic path through the easing, there being an odd number ofsuch pins for the purpose described.

I 6. The combination of a casinghaving an openlng, a plug of non-magnetic material therein, a bar magnet rotatably mounted at its center within the casing and adjacent the plug, means for rotating the magnet, pivot bearings carried by the plug on its outer face, a shaft mounted in said bearing,

- a second magnet on the shaft directly oppo site the first named magnet and adapted to move in unison therewith, and spaced pins having their ends embedded in the plug and arranged in a circle in the path of the flow of magnetic flux.

In Witness whereof, I have set my hand this 11th day of December, 1913.

LUCIAN A. SHELDON. Witnesses:

BENJAMIN B. HULL, MARGARET E. WOOLLEY. 

